The proposed use of lasers in satellite ranging and optical communications requires an analysis of the effects of natural and man-made radiation upon the performance of these systems. Spaceborne laser systems will be exposed to high energy protons and electrons in the Van Allen belts, solar flares, and galactic cosmic rays. The use of on-board radioisotope thermoelectric generators will expose system components to neutrons and gamma rays. This paper reviews the effects of this radiation upon two types of laser range finders: Nd:YAG (1.06 pm) and CO2 (10.6 gm). The radiation-induced degradation in component response is translated into reductions in system performance. We conclude with recommended nuclear hardening design guidelines.